1. Field of the Invention
The present invention relates generally to improved methods for collecting cells for subsequent analysis and more specifically, for collecting purified cells from a flow cytometer onto a solid support. Upon absorption onto the solid support, cell lysis occurs and genetic material from the lysed cells is immobilized on the solid support allowing analysis of the genetic material directly on the solid support or following an elution step.
2. Description of the Related Art
One method for isolating heterogeneous cell populations is by fluorescence activated cell sorting, originally developed by Herzenberg and co-workers (Science. 1969 166(906):747–9; J Histochem Cytochem. 1976 24(1):284–91; Clin Chem. 1973 19(8):813–6; Ann. N.Y. Acad. of Sci. 1975 254:163–171). Using this technology, cells are labeled with antibodies conjugated to dyes. By combining multiple immunofluorescent labels with the light scattering properties of the cells it is possible to distinguish between cells of different lineages based on expression of unique cell surface antigens (See for example, Loken M R, et al., in Flow Cytometry in Hematology. Laerum O D, Bjerksnes R. eds. Academic Press. New York, pp 31–42, 1992; Civin C I, et al., in “Concise Reviews in Clinical and Experimental Hematology” Martin J. Murphy ed. AlphaMed Press, Dayton Ohio, 1992, pp 149–159). Populations identified by the flow cytometer can then be isolated using the cell sorting electronics available on the instrument. Two or more fractions can be obtained in pure or enriched forms for further analysis using molecular biology techniques.
One technical problem is the difficulty encountered in working with small numbers of purified cells or small sample volumes. It is well known in the field that a significant proportion of cells are lost in processing small numbers of cells, typically by adhesion to vessel walls, pipettes or other charged surfaces in which the cells come in contact.
Accordingly, there remains a need in the art for improved methods for collecting purified cells, particularly when handling small numbers of cells and/or small sample volumes. The present invention fulfills this need and other needs.